Stepwells (Baolis) Of Delhi

Current list of existing, buried, or destroyed Baolis 
As per the last survey done by the Archeological Survey of India, there were 32 step-wells in Delhi, of which only 16 are existing today. Originally, there were at least 100 'Baolis' across Delhi as per old journals and books written by historians but there is no confirmed/official documentation of the same

The Lahorheri Stepwell, A16th century step-well was built by the Lodhi Dynasty
 A typical design of a stepwell
There is a main deeper well connected to the confined underground aquifer which supplies water to the tank. The well water was used for drinking. The tank water was used for bathing and washing

Agrasen ki Baoli, A 14th-century step-well was built by King Agrasen. 

Rajon ki Baoli (left) is a 16th-century stepwell built by Sikandar Lodi. Gandhak (sulfur) ki Baoli (right) is a 13th-century stepwell built by Sultan Iltutmish. This well was fed by a sulfur spring with curative properties

Purana Qila Baoli (left) is a 16th-century stepwell built by Ruler Sher Shah Suri. Wazirpur Gumbad Baoli (right) was supposedly built during the reign of the Lodi Dynasty between 1451 and 1526. The actual details are still unknown.

Feroz Shah Kotla Baoli is a 14th-century step-well, built by Ruler Firoz Shah Tughlaq. This is one of the differently designed Baolis in Delhi. Unlike the linear Baolis, this one was designed in a circular form and it was completely covered. The roof was destroyed over time and Baoli is inaccessible to visitors due to accidents at the site in recent years.

Built by Ghiyassuddin Tughlaq in the 14th Century the Tughlaqabad Fort step-wells were also different in design. These wells were squarish in structure with side access. About 14 wells were supposedly constructed in the fort of which only two remain. The east Baoli is closed to the public due to its dilapidated condition.

The Lal Qila Baoli was probably built by the Tughlaq Dynasty in the 14th century or earlier. It was reconstructed or renovated by the Lodis considering the workmanship it currently has and was later renovated again by the Mughals during the construction of the Red Fort.

The Nizammudin Dargah Baoli (left) was built in the 14th century by Ghiyassuddin Tughlaq. The Baoli is in use and is fed by some 7 underground springs.  The Arab Sarai Baoli (right) was built in the 17th century by Emperor Jehangir 

The Qutub Sahib Baoli (left) is a 13th-century step-well built by Sultan Iltutmish. The Pir Ghalib or Hindu Rao Hospital Baoli (right) is a 14th-century step-well built by Feroz Shah Tughlaq. Both are in the process of revival. They were in a horrible state as can be seen.

The oldest Baoli was supposed to have been in Anangtal behind Jogmaya temple, built in the 12th century or earlier. There are some ruins found in the forest area but without excavations, it will be difficult to say where the Baoli existed and how old was it. 

The Largest Baoli areawise in Delhi is Feroz Shah Kotla Baoli. The deepest Baoli existing Baoli is the Gandhak Baoli and the deepest dried-up Baoli is the East Baoli in Tughlaqabad Fort.